Endoscopic instrument for tissue identification

ABSTRACT

A method for identifying and treating tissue includes providing an electrosurgical treatment device including an electrode assembly. One or more electrical property values of target tissue are measured. The measured electrical property values of the target tissue are compared against electrical property values of known tissue types. A tissue type of the target tissue is identified. An energy delivery configuration of the electrosurgical treatment device is adjusted to the type of target tissue. The electrosurgical treatment device is activated to treat the target tissue.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of U.S. patent applicationSer. No. 15/188,514 filed on Jun. 21, 2016, which is a continuation ofU.S. patent application Ser. No. 14/447,888 filed on Jul. 31, 2014, nowU.S. Pat. No. 9,370,314, which is a continuation of U.S. patentapplication Ser. No. 13/539,875 filed on Jul. 2, 2012, now U.S. Pat. No.8,801,709, which is a divisional of U.S. patent application Ser. No.12/366,298 filed on Feb. 5, 2009, now U.S. Pat. No. 8,221,418, whichclaims priority to U.S. Provisional Application No. 61/026,788 filed onFeb. 7, 2008, the entire contents of each of which are incorporatedherein by reference.

BACKGROUND Technical Field

The present disclosure relates to open or endoscopic instruments andmethod for treating tissue, and more particularly, the presentdisclosure relates to surgical instruments including an assembly fordetermining tissue type and the condition of the tissue being treatedutilizing electrical property measurements of the tissue.

Background of Related Art

A hemostat or forceps is a simple plier-like tool that uses mechanicalaction between its jaws to constrict vessels and is commonly used inopen surgical procedures to grasp, dissect and/or clamp tissue.Electrosurgical forceps utilize both mechanical clamping action andelectrical energy to affect hemostasis by heating the tissue and bloodvessels to coagulate, cauterize and/or seal tissue.

Over the last several decades, more and more surgeons are complementingtraditional open methods of gaining access to vital organs and bodycavities with endoscopes and endoscopic instruments that access organsthrough small puncture-like incisions. Endoscopic instruments areinserted into the patient through a cannula, or port, that has been madewith a trocar. Typical sizes for cannulas range from three millimetersto twelve millimeters. Smaller cannulas are usually preferred, which, ascan be appreciated, ultimately presents a design challenge to instrumentmanufacturers who must find ways to make surgical instruments that fitthrough the cannulas.

As mentioned above, by utilizing an electrosurgical instrument, asurgeon can either cauterize, coagulate/desiccate and/or simply reduceor slow bleeding, by controlling the intensity, frequency and durationof the electrosurgical energy applied through the jaw members to thetissue. The electrode of each jaw member is charged to a differentelectric potential such that when the jaw members grasp tissue,electrical energy can be selectively transferred through the tissue.

Bipolar electrosurgical instruments are known in the art, as are otherelectrosurgical instruments. Commonly owned U.S. Patent ApplicationPublication No. 2007-0062017, discloses a bipolar electrosurgicalinstrument, the entire contents of which is hereby incorporated byreference herein. Conventional bipolar electrosurgical instruments mayinclude a cutting blade, fluid applicator, stapling mechanism or otherlike feature, in various combinations.

Different types of tissues, i.e. vessels, ligaments, may requiredifferent energy delivery configurations to effect proper sealing. Whilea specific energy delivery configuration may be adequate for treating anartery or vein, the same energy delivery configuration may not besuitable for treating a ligament. Although a majority of the time thetype of tissue being treated is either known or visually apparent, theremay be instances where a surgeon is unable to visually determine thetype of tissue being sealed. Treating non-target type tissue with anenergy configuration configured for a target type tissue may causedamage to the non-target tissue and/or result in failure to effectproper treatment.

Traditional methods for identifying tissue within the body are based onsensing physical characteristics or physiological attributes of bodytissue, and then distinguishing normal from abnormal states from changesin the characteristic or attribute. For example X-ray techniques measuretissue physical density, ultrasound measures acoustic density, andthermal sensing techniques measures differences in tissue heat. Ameasurable electrical property of tissue is its impedance; i.e., theresistance tissue offers to the flow of electrical current through it.Values of electrical impedance of various body tissue are well knownthrough studies on intact human tissue or from excised tissue madeavailable following therapeutic surgical procedures.

Various methods and apparatus for measuring tissue electrical propertiesare known. For example, U.S. Pat. No. 5,380,429 to Withers, discloses amethod and apparatus for displaying multi-frequency bio-impedance, andU.S. Patent Publication No. 2006/0004300, discloses a method ofmulti-frequency bio-impedance determination, the entire contents of eachof which are hereby incorporated by reference herein.

Once the type of tissue is identified, determining the condition orstate of the tissue is important in effectively and properly treatingthe tissue. Diseased, ischemic, or otherwise compromised tissue may notadequately seal, or may require alteration to the energy delivered tothe tissue. It is well documented that a decrease in electricalimpedance occurs in tissue as it undergoes cancerous changes. Using anyof the known methods for measuring tissue impedance, the tissueimpedance may be measured, and the resulting measurements may becompared against known impedance measurements for like tissue.Difference between the readings may be used to indicate the condition ofthe tissue. Thus, knowledge of the electrical properties of tissue maybe used to identify the type of tissue and/or the condition of thattissue.

SUMMARY

The present disclosure relates to surgical instruments including anassembly for determining tissue type and the condition of the tissuebeing treated utilizing tissue electrical property measurements.

Provided is a bipolar forceps including a handle, a shaft extending fromthe handle and having opposing jaw members at a distal end thereof,wherein the jaw members are configured for sealing tissue, and anelectrode assembly for measuring an electrical property of a targettissue, the electrode assembly being mounted on at least one of saidopposing jaw members.

The electrode assembly includes a plurality of electrodes and isconfigured to be operably connected to a processing unit. The processingunit may be configured to selectively measure at least one of animpedance, conductance and capacitance of the target tissue. Theprocessing unit may be configured to determine a type of target tissueand/or a condition of the target tissue. The processing unit may beconfigured to alert a user when a predetermined condition has beensatisfied. The forceps may be operably connectable to a generator. Thegenerator may include a processing unit for determining tissueimpedance.

Also provided is a method for identifying and treating tissue includingproviding a electrosurgical treatment device including an electrodeassembly for measuring one or more electrical properties of a targettissue, the electrode assembly being mounted on a distal end thereof,measuring the one or more electrical characteristics of the targettissue, comparing the measured electrical property values of the targettissue against electrical property values of known tissue types,identifying a tissue type of the target tissue, adjusting an energydelivery configuration of the electrosurgical treatment device to thetype of target tissue, and activating the electrosurgical treatmentdevice to treat the target tissue.

The electrode assembly may include one or more electrodes. The electrodeassembly includes a base having an electrode extending coaxiallytherethrough. The coaxially extending electrode may be operablyconnected to a high frequency generator. The high frequency generatormay be capable of generating a frequency between 30 MHz and 30 GHz. Themethod may further include measuring an electrical property of thetarget tissue following treatment, and the determining the effectivenessof the treatment.

Further provided is a system for identifying and treating tissueincluding an electrosurgical treatment device, a generator operablyconnected to the electrosurgical treatment device for deliveringelectrosurgical energy thereto, an electrode assembly extending from adistal end of the electrosurgical treatment device, and a processingunit operably connected to the electrode assembly for measuring tissueone or more electrical properties of the tissue. The electrode assemblymay be selectively extendable from the distal end of the electrosurgicaltreatment device and may include an electrode extending coaxiallytherethrough. The electrode may be operably connected to a highfrequency generator. The electrode assembly may instead include at leasta pair of electrodes or an array of electrodes.

A system for identifying tissue is also provided including a housing, anelongated body extending distally therefrom, the elongated body definingat least one lumen therethrough, and a probe operably extendable throughthe at least one lumen, the probe including at least one electrodedetermining at least one electrical property of tissue. The at least oneelectrode may extend coaxially through the probe. The system may furtherinclude a processor configured for identifying tissue using thedetermined electrical property. The array of electrodes may include atleast four electrodes arranged linearly. The array of electrodes mayinstead include a plurality of electrodes arranged in an array.

BRIEF DESCRIPTION OF THE DRAWINGS

Various embodiments of the subject instrument are described herein withreference to the drawings wherein:

FIG. 1A is a left, perspective view of an endoscopic bipolar forcepsincluding a multi-electrode assembly for measuring tissue impedanceaccording to an embodiment of the present disclosure;

FIG. 1B is a left, perspective of an open bipolar forceps including amultielectrode assembly for measuring tissue impedance according to anembodiment of the present disclosure;

FIG. 2 is a schematic illustration of an electrosurgical systemincluding the endoscopic bipolar forceps of FIG. 1A;

FIG. 3 is an enlarged front view of a jaw member including themultielectrode assembly;

FIG. 3A is an enlarged view of the indicated area of detail of FIG. 3;

FIG. 4 is a side elevational view of the jaw member of FIG. 3;

FIG. 5 is an enlarged front elevational view of an alternate embodimentof a jaw member including another multi-electrode assembly for measuringtissue impedance;

FIG. 5A is an enlarged view of the indicated area of detail of FIG. 5;

FIG. 6 is a side elevational view of the jaw member of FIG. 5;

FIG. 7 is an enlarged front elevational view of yet another jaw memberthe present disclosure including yet another multi-electrode electrodeassembly;

FIG. 7A is an enlarged view of the indicated area of detail of FIG. 7;

FIG. 8 is a side elevational view of the jaw member of FIG. 7;

FIG. 9 is a perspective view of an alternate embodiment of anelectrosurgical instrument extending through a working channel of anendoscope;

FIG. 10 is an enlarged side view of the electrode assembly of theendoscopic device of FIG. 9;

FIG. 11 is an enlarged end view of an alternate embodiment of anelectrode assembly;

FIG. 12 is an enlarged end view of another embodiment of an electrodeassembly;

FIG. 13A is a side view of another embodiment of an electrode assembly;and

FIG. 13B is an enlarged distal end view of the electrode assembly ofFIG. 13A.

DETAILED DESCRIPTION

Referring now to FIGS. 1-4, an embodiment of an electrosurgicalinstrument according to the present disclosure is shown generally asbipolar forceps 100. Bipolar forceps 100 include a housing 120, a handleassembly 130, a rotating assembly 180, a trigger assembly 170 and an endeffector assembly 110 that mutually cooperate to grasp, seal and dividetubular vessels and vascular tissue. Although the following disclosurefocuses predominately on discussion of a bipolar forceps 100 for use inconnection with endoscopic surgical procedures, an open forceps 100′ arealso contemplated for use in connection with traditional open surgicalprocedures and are shown by way of example in FIG. 1B. For the purposesherein, the endoscopic version is discussed in detail; however, it iscontemplated that open forceps 100′ also include the same or similaroperating components and features as described below.

Bipolar forceps 100, 100′ are substantially identical in form andfunction to bipolar forceps 10, 10′ described in detail in commonlyowned, U.S. Patent Publication No. 2007-0062017, the entire contents ofwhich is hereby incorporated by reference herein. Thus, the form andfunction of bipolar forceps 100, 100′ will be discussed only to theextent necessary to describe the improvement thereto. The aspects of thepresent disclosure may be incorporated into any suitable electrosurgicalinstrument.

Turning now to FIGS. 1A and 2, forceps 100 includes a shaft 112 that hasa distal end 114 dimensioned to mechanically engage the end effectorassembly 110 and a proximal end 116 that mechanically engages housing120. In the drawings and in the descriptions that follow, the term“proximal,” as is traditional, will refer to the end of the forceps 100that is closer to the user, while the term “distal” will refer to theend which is further from the user.

As seen in FIG. 1A, handle assembly 130 includes a fixed handle 160 anda movable handle 140. Fixed handle 160 is integrally associated withhousing 120 and handle 140 is movable relative to fixed handle 160.Rotating assembly 80 is preferably attached to a distal end of housing120 and is rotatable approximately 180 degrees in either direction abouta longitudinal axis “A.”

Turning briefly to FIGS. 3 and 4, end effector assembly 110 includesfirst and second jaw members 212, 214. First and second jaw members 212,214 are operably connected to handle 140 (FIG. 1A). First and second jawmembers 212, 214 are configured to approximate towards one another uponactivation of handle 140. First and second jaw members 212, 214cooperate to grasp and seal target tissue therebetween.

As best seen in FIGS. 1A and 2, forceps 100 also include an electricalinterface or plug 300 that connects the forceps 100 to a source ofelectrosurgical energy, e.g., a generator 10, and a processing unit 20.Generator 10 and processing unit 20 may be combined to form a singlegenerator/processing unit 30. For ease of disclosure, further referencesto processing unit 20 may also be applicable to generator/processingunit 30. Generator 10 may be one of many sold by Valleylab—a division ofTyco Healthcare LP, located in Boulder Colo., used as a source ofelectrosurgical energy, e.g., FORCE EZ™ Electrosurgical Generator, FORCEFX™ Electrosurgical Generator, FORCE 1C™, FORCE 2™ Generator, SurgiStat™II. One such system is described in commonly-owned U.S. Pat. No.6,033,399 entitled “ELECTROSURGICAL GENERATOR WITH ADAPTIVE POWERCONTROL,” the entire contents of which is hereby incorporated byreference herein. Other systems have been described in commonly-ownedU.S. Pat. No. 6,187,003 entitled “BIPOLAR ELECTROSURGICAL INSTRUMENT FORSEALING VESSELS,” the entire contents of which is hereby incorporated byreference herein.

Generator 10 and/or generator/processing unit 30 may include varioussafety and performance features including isolated output, independentactivation of accessories, and the Valleylab REM™ Contact QualityMonitoring System, which may substantially reduce the risk of burnsunder the patient return electrode. The electrosurgical generator mayinclude Valleylab's Instant Response™ technology features that providean advanced feedback system that senses changes in tissue 200 times persecond and adjusts voltage and current to maintain appropriate power.

Processing unit 20 is operably connected to an electrode assembly 50(FIG. 3). As will be discussed in further detail below, electrodeassembly 50 may be mounted on a distal end of forceps 100. Processingunit 20 operates in a manner similar to known tissue impedance measuringdevices. Briefly, a predetermined energy signal is produced byprocessing unit 20 and applied to the target tissue (not explicitlyshown) through electrode assembly 50. The resultant electrical responseof the tissue to the signal may then be measured and converted into animpedance value. By comparing the tissue impedance measurements withknown tissue impedance measurements processing unit 20 may determine thetype of tissue being in contact with electrode assembly 50.

The electrical current produced by processing unit 20 may vary dependingon the type of tissue being identified. Processing unit 20 mayconfigured to produce AC and/or DC current. Processing unit 20 may beconfigured to generate an electrical signal having a frequency rangingfrom RF (100 kHz) upwards of microwaves (low MHz to GHz). Depending onthe application processing unit 20 may produce a signal of constantfrequency, or may instead perform a frequency sweep. Bipolar forceps 100may include more than one electrode assembly 50 connected to processingunit 20 for measuring tissue impedance. As will be discussed in furtherdetail below, the one or more electrode assemblies 50 may includedifferent electrode configurations depending on the tissue type and/orsignal frequency being tested. Processing unit 20 may include anysuitable methods of increasing the accuracy and consistency of thetissue electrical property measurements, e.g. filters andmulti-frequency readings.

Processing unit 20 may operate in a number of modes. Processing unit 20may be configured to alert a user when electrode assembly 50 hascontacted a specific tissue type. In this manner, a user would setprocessing unit 20 to scan for a particular tissue type. Processing unit20 would produce an electrical signal configured for best identifyingthe tissue type. The electrical signal produced by processing unit 20may be manually determined by the user or may instead be automaticallydetermined by processing unit 20. The electrical signal produced mayinclude a specific frequency or range of frequencies and/or may includea specific signal configuration. Electrode assembly 50 may be placed incontact over a portion of tissue. As electrode assembly 50 contactstissue of the target type, as determined by processing unit 20 bycomparing the electrical property measurements with known electricalproperty measurements of like tissue, processing unit 20 may alert theuser. The alert may be audio and/or visual. An audio and/or visualindicator 22, 24 (FIG. 2) may be included in/on processing unit 20and/or bipolar forceps 100.

Identifying tissue type by comparing the electrical propertymeasurements of the tissue with electrical property measurements fromknown tissue type requires the availability of electrical propertymeasurements of known tissue. These measurements may not always beavailable, or may vary depending on the environment in which the targettissue is situated. For example, tissue located within the digestivetract and exposed to digestive enzymes may have different electricalproperty measurements from tissue exposed to air. When implementing thecomparative technique described above, knowledge of the electricalproperty of the tissue exposed to digestive enzymes would be of littleuse when compared to the electrical properties of tissue exposed to air.When electrical property measurements of known tissue are not available,the type of tissue may be determined by comparing the electricalproperty measurements of the target tissue with the electrical propertymeasurements of the surrounding tissue. Since fat exhibits differentelectrical properties from muscle, and muscles exhibits differentelectrical properties that connective tissue, by comparing the relativeelectrical property measurements of different tissue types within thesame environment, i.e. saturated in digestive enzymes, or exposed toair, the differences in the relative electrical property measurements ofthe various tissues may be used to distinguish the various tissue types.Another example is the difference between a suspicious mass and thesurrounding normal tissue may be used to determine its nature as benignor malignant.

Alternatively, processing unit 20 may be configured to determine thetype of tissue in contact with electrode assembly 50. In this manner,processing unit 20 produces an electrical signal spanning a wide rangeof frequencies and/or wave configurations. The range of frequenciesand/or wave configurations may be limited by the user. As before, thetissue electrical property measurements (magnitude and/or phase) arecompared against electrical property measurements for known tissue. Onceprocessing unit 20 has determined the type of tissue the user may bealerted. The alert may be audio and/or visual.

Once the type of tissue is known, whether through visual inspection ortissue impedance measurements, the condition of the tissue may also bedetermined. Using techniques similar to that described above, thecondition of the tissue may also be determined. Knowing the type oftissue being examined is not necessary; however, it permits a user tolimit the frequency range and/or signal configuration of the electricalsignal applied to the tissue, thereby reducing the time for a result.The condition of the tissue may be determined by comparing theelectrical property measurements with electrical property measurementsof tissue of a known condition. In addition, the condition of the tissuemay be determined by comparing the electrical property measurements ofportions of the same tissue. Processing unit 20 may provide the userwith an audio and/or visual alert as to the condition of tissue incontact with electrode assembly 50.

Tissue has many electrical properties and there are many known methodsfor measuring these electrical properties. Although the followingdiscussion will relate to a four-electrode method of measuring tissueimpedance, other methods of measuring tissue electrical properties havebeen contemplated by the present disclosure. In the four-electrodemethod, four equidistant electrodes are placed in contact with orpenetrate into the tissue to be tested. In one procedure utilizing thefour-electrode method, a sinusoidal voltage is applied to the tissueacross two electrodes and the resultant sinusoidal current flow throughthe tissue is measured. The magnitude of the tissue impedance may bedetermined as the ratio of the root-mean-square (RMS) voltage and thecurrent values. The phase angle of the tissue impedance may bedetermined as the delay in radians of the peak sinusoidal current withrespect to the peak sinusoidal voltage. By comparing the resultingimpedance values with known values for various body tissue, the tissuetype may be determined. It should be appreciated that the aspects of thepresent disclosure should not be limited to the methods of determiningtissue impedance disclosed herein. Any suitable method for measuringtissue electrical properties may be incorporated into the embodiments ofthe present disclosure.

Turning now to FIGS. 3-8, various embodiments of opposing jaw membersincluding one or more multi-electrode assemblies that operate in amanner as discussed above are shown. Referring initially to FIGS. 3-4,end effector 110 of bipolar forceps 100 includes an electrode assembly50. Electrode assembly 50 is mounted on a distal end 212 b of first jawmember 212. As will be discussed below, alternate embodiments of bipolarforceps 100 may include a plurality of electrode assemblies mounted atvarious locations on first and/or second jaw members 212, 214. Electrodeassembly 50 includes four electrodes 51, 52, 53, 54. In the illustratedembodiment, electrodes 51, 52, 53, 54 form substantially planar membershaving a substantially similar size and configuration. Electrodes 51,52, 53, 54 are spaced an equidistance apart and may be formed of ametal, an alloy or other suitable material. Electrodes 51, 52, 53, 54 ofelectrode assembly 50 are operably connected to processing unit 20 (FIG.3).

In operation, electrodes 51, 52, 53, 54 of electrode assembly 50 areplaced in contact with the tissue to be identified. First and second jawmembers 212, 214 may be in an open or closed condition. Processing unit20 produces an electric signal that is directed into the target tissuethrough outer electrodes 51, 54. Processing unit 20 may be configured tocontinuously produce a signal, or instead bipolar forceps 100 mayinclude a button or lever 122, 124 mounted on housing 120 (FIG. 1A)and/or processing unit 20 (FIG. 2) for activating processing unit 20. Asdiscussed above, depending on the application, the electric signal maybe of a specific frequency or range of frequencies and of anyconfiguration. The respective portion of tissue disposed between outerelectrode 51 and inner electrode 52, and outer electrode 54 and innerelectrode 53 functions to complete a circuit path therebetween. Theseportions of tissue produce characteristic tissue responses based on thesignals delivered to electrodes 51, 52, 53, 54 by processing unit 20.The resulting tissue response is acquired by inner electrodes 52, 53.Also, as discussed above, the measurements of the tissue response may beused to calculate the tissue impedance. By comparing the tissueimpedance values of the target tissue with impedance values of knowntissue, the type of tissue being contacted (e.g., lung, liver, muscle,etc.) may be determined.

As discussed above, once the tissue type has been determined, eitherthrough visual inspection, by comparing tissue electrical propertymeasurements or with another suitable method, the condition of thetissue may also be determined. By directing an electric signal of afrequency or range of frequencies configured for the particular tissuetype being tested and measuring the resultant impedance values, thecondition of the tissue may be determined. For example, healthy tissuemay be distinguished from cancerous tissue. Additionally, the stage ofdevelopment of the cancer may also be determinable using the tissueimpedance measurements.

Once the tissue type and condition of the tissue have been identified,bipolar forceps 100 may operate as a conventional bipolar vessel sealer.The energy delivery configuration of generator 10 may be adjusted inaccordance with the identified tissue type being sealed. The closurepressure of first and second jaw members 212, 214 may also be adjustedin view of the type of tissue being sealed and/or the condition of thetissue being sealed. While four electrodes, 51, 52, 53, 54 are shown asforming a part of multielectrode assembly 50, any suitable number ofelectrodes may be used either greater than or less than four in formingmulti-electrode assembly 50.

Turning now to FIGS. 5-6, in an alternate embodiment of an end effectorof the present disclosure, end effector 220 includes electrode assembly150 mounted on a distal end 212 b of first jaw member 212. Alternately,electrode assembly 150 may be mounted on distal end 214 b of second jawmember 214. Electrode assembly 150 includes electrodes 151, 152, 153,154. Electrodes 151, 152, 153, 154 include piercing or penetratingmembers 151 a, 152 a, 153 a, 154 a, respectively, for penetrating thetarget tissue to be identified. By using piercing members 151, 152, 153,154 to penetrate the tissue a relatively truer or more accurate tissueimpedance measurement may be obtained. Piercing members 151 a, 152 a,153 a, and 154 a may be of any suitable dimension and of any suitableconfiguration. In an alternate embodiment, electrodes 151, 152, 153, 154and/or piercing members 151 a, 152 a, 153 a, 154 a may be selectivelyretractable and/or extendable.

With reference now to FIGS. 7-8, in another embodiment of an endeffector of the present disclosure, end effector 310 includes electrodeassembles 250, 350, 450, and 550. Electrode assemblies 250, 550 are eachsubstantially similar to electrode assemblies 50, 150 describedhereinabove, and will therefore only be described as relates to thedifferences therebetween. Electrode assembly 250 or 550 includes anarray of electrodes 251 a-d, 252 a-d, 253 a-d, 254 a-d arranged in anysuitable configuration (e.g. rectilinear) and in any suitable quantity.Electrodes 251 a-d, 252 a-d, 253 a-d, 254 a-d of electrode assembly 250are each operably connected to processing unit 20 (FIG. 2). Processingunit 20 may be configured to selectively apply electric signals throughany or all of electrodes 251 a-d, 252 a-d, 253 a-d, 254 a-d in a mannersimilar to that described above to determine impedance of a targettissue. The rectilinear array of electrode assembly 240 enables a userto select the electrode configuration best suited for measuring andidentifying tissue of a particular type.

With continued reference to FIGS. 7-8, electrode assemblies 350, 450 arepositioned on an inner surface of first and second jaw member 312, 314,respectively, e.g., on a tissue contacting surface thereof. Electrodeassemblies 350, 450 operate in a manner substantially similar toelectrode assemblies 250, 550 described hereinabove. By includingelectrode assemblies 350, 450 on an inner surface of first and secondjaw member 312, 314, respectively, the type of tissue being graspedtherebetween may be determined. Such identification of tissue may occurat any time prior to a sealing of the target tissue.

Electrode assemblies 50, 150, 250, 350, 450, 550 may also be usedpost-sealing to determine if a proper seal has been formed. By measuringthe impedance of a post-sealing tissue, and comparing the impedancemeasurements thereof with known values of properly sealed tissueprocessing unit 20 (FIG. 2) may alert a user of the condition of thepost-sealing tissue. Alternatively, processing unit 20 may compare thepost-sealing impedance measurements of the tissue with the pre-sealingimpedance measurements thereof to determine if a proper seal has beenaffected.

Referring now to FIGS. 9-12, another embodiment of the presentdisclosure is shown generally as endoscopic device 500. Briefly,endoscopic device 500 includes a housing 520 and an elongated tubularmember 512 extending from the housing 520. Tubular member 512 defines aplurality of working channels or lumens 515 a, 515 b, 515 c extendingtherethrough. Proximal end 516 of tubular member 512 mechanicallyengages or is supported on or by housing 520. Tubular member 512 may berigid, flexible and/or selectively rigid. Housing 520 may include asteering mechanism 580 for controlling or articulating distal end 514 oftubular member 512 in any suitable manner. Working channels or lumens515 a, 515 b, 515 c may be configured to receive an endoscope,electrosurgical instrument, snare or the like therethrough.

As seen in FIG. 9, an electrode assembly 650 extends through workingchannel or lumen 515 a of tubular member 512. As seen in FIG. 10,electrode assembly 650 includes a plurality of electrodes 650 a mountedabout a probe-like base or core member 600. Electrodes 650 a may beaxially spaced apart from one another along a length of core member 600.Electrode assembly 650 may include a cauterization and/or sealing tip605 for treating tissue. As seen in FIG. 10, tip 605 may be sharpened,tapered and/or beveled.

Electrode assembly 650 is operably connected to a processing unit20′(see FIG. 9). Processing unit 20′ is substantially similar toprocessing unit 20 described hereinabove and thus will not be describedin further detail herein. Additionally, processing unit 20′ may includea drive mechanism 25 for advancing and retracting multi-electrodeassembly 650 from within channel 515 a of tubular member 512.

Alternatively, as seen in FIGS. 11 and 12, base or core member 600 mayinclude a flattened distal end surface 600 a. Flattened distal endsurface 600 a may include multi-electrode assemblies of multipleconfigurations. As shown in FIG. 11, base member 600 may include alinear array of electrodes 750 provided on distal end surface 600 a(e.g., an exemplary four electrodes being shown), or a grid-like orrectangular array of electrodes 850 provided on distal end surface 600 a(e.g., an exemplary 4×4 rectangular array being shown) multi-electrodeassembly 850. Electrode arrays 750, 850 operate in a manner similar tothe multi-electrode assemblies or arrays described above and thus willnot be described in further detail herein.

With reference to FIGS. 13A and 13B, in yet another embodiment, basemember 600 defines a sheath 602 that includes a coaxially electrode 950extending a length thereof. In this manner, only a distal end 950 a ofelectrode 950 is exposed. It is envisioned that distal end 950 a ofelectrode 950 may form a pointed surface for penetrating tissue.Coaxially electrode 950 may be operably connected to a high frequencygenerator “HFG” capable of generating a signal between 30 MHz-30 GHz.

While several embodiments of the disclosure have been shown in thedrawings, it is not intended that the disclosure be limited thereto, asit is intended that the disclosure be as broad in scope as the art willallow and that the specification be read likewise. Therefore, the abovedescription should not be construed as limiting, but merely asexemplifications of preferred embodiments. Those skilled in the art willenvision other modifications within the scope and spirit of the claimsappended hereto.

What is claimed is:
 1. A method for identifying tissue, the methodcomprising: contacting tissue with at least one jaw member of a pair ofopposed jaw members; applying an electrical signal to the tissue througha first electrode coupled to the pair of opposed jaw members; receiving,through a second electrode coupled to the pair of opposed jaw members,an electrical signal emitted by the tissue in response to the electricalsignal applied to the tissue; determining an electrical property of thetissue based on the electrical signal emitted by the tissue; andcomparing the determined electrical property of the tissue with at leastone known electrical property to identify a type of the tissue.
 2. Themethod according to claim 1, further comprising adjusting a frequency ofthe electrical signal applied to the tissue through the first electrodebased on the identified type of the tissue.
 3. The method according toclaim 1, further comprising adjusting a wave configuration of theelectrical signal applied to the tissue through the first electrodebased on the identified type of the tissue.
 4. The method according toclaim 1, further comprising identifying a condition of the tissue basedon the comparison.
 5. The method according to claim 1, furthercomprising controlling delivery of electrosurgical energy to the tissuevia at least one of the pair of opposed jaw members based on thecomparison.
 6. The method according to claim 1, wherein determining theelectrical property of the tissue includes determining an impedance ofthe tissue.
 7. The method according to claim 1, wherein determining theelectrical property of the tissue includes determining a conductance ofthe tissue.
 8. The method according to claim 1, further comprisingdelivering electrosurgical energy to the tissue to treat the tissue anddetermining an electrical property of the treated tissue.
 9. The methodaccording to claim 1, wherein identifying the type of the tissueincludes comparing the determined electrical property of the tissue withan electrical property of tissue that is adjacent the tissue to identifya type of the tissue.
 10. The method according to claim 1, wherein thefirst electrode is coupled to a first jaw member of the pair of opposedjaw members and the second electrode is coupled to a second jaw memberof the pair of opposed jaw members.
 11. The method according to claim 1,wherein applying the electrical signal to the tissue includes applyingthe electrical signal when the pair of opposed jaw members are in aclosed condition to grasp the tissue.
 12. A method for identifyingtissue, the method comprising: applying an electrical signal to tissuethrough a first electrode coupled to a pair of opposed jaw members;receiving, through a second electrode coupled to the pair of opposed jawmembers, an electrical signal emitted by the tissue in response to theelectrical signal applied to the tissue; determining an electricalproperty of the tissue based on the electrical signal emitted by thetissue; and comparing the determined electrical property of the tissuewith at least one known electrical property to identify a type of thetissue.
 13. The method according to claim 12, further comprisingcontrolling delivery of electrosurgical energy to the tissue via atleast one of the pair of opposed jaw members based on the comparison.14. The method according to claim 12, wherein determining the electricalproperty of the tissue includes determining an impedance of the tissue.15. The method according to claim 12, wherein determining the electricalproperty of the tissue includes determining a conductance of the tissue.16. The method according to claim 12, further comprising adjusting atleast one of a frequency or a wave configuration of the electricalsignal applied to the tissue through the first electrode based on theidentified type of the tissue.
 17. The method according to claim 12,wherein the first electrode is coupled to a first jaw member of the pairof opposed jaw members and the second electrode is coupled to a secondjaw member of the pair of opposed jaw members.
 18. The method accordingto claim 12, wherein applying the electrical signal to the tissueincludes applying the electrical signal when the pair of opposed jawmembers are in a closed condition to grasp the tissue.
 19. A method foridentifying tissue, the method comprising: applying an electrical signalto tissue through at least one of a pair of opposed jaw members;receiving, through at least one of the pair of opposed jaw members, anelectrical signal emitted by the tissue in response to the electricalsignal applied to the tissue; determining an electrical property of thetissue based on the electrical signal emitted by the tissue; andcomparing the determined electrical property of the tissue with at leastone known electrical property to identify a type of the tissue.
 20. Themethod according to claim 19, further comprising contacting the tissuewith at least one of the pair of opposed jaw members.